Principles of Disinfection and Sterilization in the outpatient setting

1. Module F Principles of Disinfection and Sterilization in the outpatient setting

2. Objectives • State the principles of disinfection and sterilization • List the current methods for disinfection and sterilization per CDC guideline recommendations

3. Spaulding Classification Spaulding Classification of Surfaces: • critical– Objects which enter normally sterile tissue or the vascular system and require sterilization • semi-critical– Objects that contact mucous membranes or non-intact skin and require high-level disinfection, which kills all but high-levels of bacterial spores • non-critical– Objects that contact intact skin but not mucous membranes, and require low-level disinfection

4. Order of resistance of microorganisms to disinfectants Prions (Creutzfeldt-Jakob Disease (CJD), mad cow disease) Spores (C. difficile) Mycobacteria (Tb) Non-enveloped viruses (norovirus) Fungi (Candida) Vegetative bacteria (MRSA, VRE) Enveloped viruses (HIV, HBV) Hardest to Kill Easiest to Kill

5. Factors influencing the efficacy of disinfection and sterilization processes • Cleaning of the object • Organic and inorganic load present • Type and level of microbial contamination • Concentration and exposure time to the disinfectant/sterilant • Nature of the object • Temperature, pH, and water hardness

6. Processing Critical Instruments

7. Processing Critical Instruments • Penetrate or enter normally sterile tissue or spaces, including the vascular system • Surgical instruments, cardiac catheters, IV devices, urinary catheters • Must be sterilized between uses or used as single-use disposable devices • Goal: Sterility = devoid of all microbial life

8. Processing Semi-critical instruments

9. Processing Semi-critical objects • Contact mucous membranes and non-intact skin • Endoscopes, Respiratory and Anesthesia equipment, endocavitary probes, tonometers, diaphragm fitting rings, vaginal speculums • Must be sterilized or immersed in high-level disinfectant • Goal: High-level disinfection = free of all microorganisms except low numbers of bacterial spores

10. High-Level Disinfectants Exposure time ≥8 -45 min (US) and temperature 20-25°C; *May cause cosmetic and functional damage

11. Cleaning of non-critical surfaces or devices

12. Non-critical instruments and devices • Contact intact skin • BP cuffs, electrocardiogram (EKG) leads, stethoscopes • Disinfect using a low level disinfectant • Goal: Kill vegetative bacteria, fungi, viruses

13. Liquid Disinfectants Exposure time ≥ 1 minute UD = Manufacturer’s recommended use dilution

14. Where are you processing your instruments? / Packaging

15. Step 1 – Cleaning instruments • Soak in enzymatic or non-enzymatic detergent • Wear the appropriate PPE • Keep instruments submerged in solution and scrub with brush

16. Ultrasonic cleaner Instrument washer Washer-disinfector Regulated by FDA Household dishwasher NOT recommended Automated Cleaning

17. Sterilization The complete elimination or destruction of all forms of microbial life by either physical or chemical processes.

18. Methods of sterilization Steam sterilization Hydrogen peroxide gas plasma Ethylene oxide Ozone Vaporized hydrogen peroxide Steam formaldehyde

19. Steam Sterilization • Advantages • Non-toxic • Cycle easy to control and monitor • Inexpensive • Rapidly microbicidal • Rapid cycle time • Least affected by organic/inorganic soils • Penetrates medical packing, device lumens

20. Steam Sterilization • Disadvantages • Deleterious for heat labile instruments • Inappropriate for heat-sensitive instruments • Inappropriate for moisture-sensitive instruments • Dulling • Rusting • Potential for burns

21. Steam Sterilization • Steam under pressure (autoclaving) • Gravity displacement • Pre-vacuum

22. Process times for packaged items

23. Dry Heat Sterilization • Transfers heat energy from air inside the oven to the instruments • Requires higher temperatures • Good for items that are likely to dull or rust in the autoclave, • Good for powders, cellulose and ink • Packaging must be able to withstand high temperatures

24. Liquid Chemical Sterilant/Disinfectants • Only for heat-sensitive critical and semi-critical devices • Powerful, toxic chemicals raise safety concerns http://www.fda.gov/cdrh/ODE/germlab.html http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/ReprocessingofSingle-UseDevices/ucm133514.htm

25. RecommendationsMethods of Sterilization • Steam is preferred for critical items not damaged by heat • Follow the operating parameters recommended by the manufacturer • Use low temperature sterilization technologies for reprocessing critical items damaged by heat • Use immediately critical items that have been sterilized by liquid sterilants(e.g. peracetic acid) immersion process (no long term storage)

26. Conclusions . . . • All sterilization processes effective in killing spores. • Cleaning removes salts and proteins and MUST precede sterilization. • Failure to clean or ensure exposure of microorganisms to sterilant could interfere with the sterilization process.

27. Monitoring

28. Sterilization Monitoring Sterilization monitored routinely by combination of physical, chemical, and biological parameters • Physical - cycle time, temperature, pressure • Chemical - heat or chemical sensitive inks that change color when germicidal-related parameters reached • Biological - Bacillus spores that directly measure sterilization

29. Monitoring of Sterilizers • Internal Chemical Indicator • Validates the sterilant penetrated the pack or tray • Detect local problem

30. Biological Monitors • Steam - Geobacillus stearothermophilus • Dry heat - B. atrophaeus (formerly B. subtilis) • Ethylene oxide (ETO) - B. atrophaeus

31. Biological Indicators

32. RecommendationsMonitoring of Sterilizers • Monitor each load with physical and chemical (internal and external) indicators. • Use biological indicators to monitor effectiveness of sterilizers at least weekly with spores intended for the type of sterilizer. • Use biological indicators for every load containing implantable items

33. RecommendationsMonitoring of Sterilizers Following a single positive biological indicator from steam sterilization: • Remove the sterilizer from service and review sterilizer instructions • Retest the sterilizer • If spore test negative, put the sterilizer back in service • If the spore test is positive: do not use until it has been inspected; and recall (to the extent possible) all items processed since the last negative spore test; challenge in three consecutive empty sterilization cycles. • Single positive biological indicator (BI) from other than steam sterilization: treat as non-sterile all items back to last load tested with negative indicator

34. Record-Keeping

35. Packaging • Peel packs • Rigid containers • Self seal roll stock • Sterile wraps woven and non-woven • Must be FDA approved

36. Loading • Place items/packages correctly and loosely into the sterilizer so as not to impede penetration of the sterilant • Peel packs and non-perforated containers (e.g., basins) should be placed on their edge

37. Sterilzation Recommendations . . . • Steam is preferred for critical (and semi-critical) items not damaged by heat • Always follow manufacturer’s operating instructions • Use an “FDA cleared” container, wrapping or packaging system that is compatible with the type of sterilization process used • Do not overload the chamber

38. RecommendationsStorage of Sterile Items • Ensure the sterile storage area is a well-ventilated area that provides protection against dust, moisture, and temperature and humidity extremes. • 8 inches from the floor8 • 5 inches from ceiling • 18 inches from ceiling if sprinkler head present • 2 inches from outside walls– 10 inches from floor • Sterile items should be stored so that packaging is not compromised. • Label sterilized items with a load number that indicates the sterilizer used, the cycle or load number, the date of sterilization, and if applicable the expiration date.

39. RecommendationsStorage of Sterile Items • Event-related shelf life recognizes that the product remains sterile until an event causes it to become contaminated (e.g. moisture). • Packages should be evaluated before use for loss of integrity. Repack and reprocess if compromised. • If time related storage of sterile items is used, label the pack at the time of sterilization with an expiration date. Once this date expires, reprocess the pack.

40. Endoscopes/Automatic endoscope reprocessors (aers)

41. Murphy Was an ICP! Murphy’s Law: “Whatever can go wrong will go wrong” Corollary: “…in the worst possible way at the worst possible time”

42. Courtesy of Bill Rutala

43. GI ENDOSCOPES AND BRONCHOSCOPES • Widely used diagnostic and therapeutic procedure • Endoscope contamination during use (GI 109 in/105 out) • Semi-critical items require high-level disinfection at a minimum • Inappropriate cleaning and disinfection has led to cross-transmission • In the inanimate environment, although the incidence remains very low, endoscopes introduce risk of disease transmission

44. TRANSMISSION OF INFECTION • Gastrointestinal endoscopy • >300 infections transmitted • 70% agents Salmonella sp. and P. aeruginosa • Clinical spectrum ranged from colonization to death (~4%) • Bronchoscopy • 90 infections transmitted • M. tuberculosis, atypical Mycobacteria, P. aeruginosa Spach DH et al Ann Intern Med 1993: 118:117-128 Weber DJ, Rutala WA Gastroint Dis 2002;87 Weber DJ, Rutala WA Infect Control Hosp Epidemiol 2012, 230-4

45. ENDOSCOPE INFECTIONS • Infections traced to deficient practices • Inadequate cleaning (clean all channels) • Inappropriate/ineffective disinfection (time exposure, perfuse channels, test concentration) • Failure to follow recommended disinfection practices (tapwater rinse) • Flaws in design of endoscopes or automatic endoscope reprocessers (AERs).

47. Steps in ENDOSCOPE DISINFECTION • CLEAN-mechanically clean with water and enzymatic or non-enzymatic cleaner • HIGH LEVEL DISINFECT/STERILIZE-immerse scope and perfuse high level disinfectant/sterilant through all channels for the time recommended by the manufacturer • RINSE-scope and channels rinsed with sterile water, filtered water, or tap water followed by alcohol • DRY-use forced air to dry insertion tube and channels • STORE-prevent recontamination

49. Minimum Effective ConcentrationChemical Sterilant • Dilution of chemical sterilant occurs during use • Test strips are available for monitoring minimum effective concentration (MEC) • Test strips for glutaraldehyde monitor 1.5% • Test strip not used to extend the use-life beyond the expiration date (date test strips when opened) • Testing frequency based on how frequently the solutions are used (used daily, test at least daily) • Record results